JPA is great but damned slow

I did some experiments with JPA, which is a really cool and simple API for entity persistence. In fact, writing an entity bean is as simple as writing a pojo plus adding some single annotations like @Entity and @Id (to identify the PK fields). That's it. Cool. :-) See this sample code: @Entity public class MySample { @Id private int x; public int getX() { return this.x; } public void setX(int x) { this.x = x; } } Yes, it's just that simple. No more DD needed (but can be optionally added for admin's customizations). And accessing objects is as simple as the following samples showcase: EntityManagerFactory emf = Persistence.createEntityManagerFactory("pu1"); EntityManager em = emf.createEntityManager(); em.getTransaction().begin(); // INSERT INTO MySample is just as easy as: MySample mySample = new MySample(); mySample.setX(12345); // Alternatively an entity can use @Generated to have an autogenerated PK! em.persist(myTable); // SELECT FROM MySample is just as easy as: Query q = em.createQuery("SELECT OBJECT(m) FROM MySample m"); // This is not SQL but OOP: All names are getting MAPPED internally! for (final MySample aSample : q.getResultList()) { System.out.println(aSample.getX()); } em.getTransaction().rollback(); (Sorry if there are any typos) Sounds cool? It IS cool! But then, I compared t...

Date: January, 03 2010
Url: http://www.java.net/blog/mkarg/archive/2010/01/03/jpa-great-damned-slow

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